This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger International Opportunities Fund (Class A / ALGAX)	$64	1.25%^(a)

(a)	Annualized.

Expenses Paid, Amount

$ 64

Expense Ratio, Percent

1.25%

^[1]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger International Opportunities Fund Class A returned a 5.23%, excluding sales load, return for the fiscal six-month period ended April 30, 2025, compared to the 6.21% return of the MSCI ACWI ex USA. During the reporting period, the largest sector weightings were Financials and Industrials. The largest sector overweight was Consumer Discretionary and the largest sector underweight was Financials.

Contributors to Performance

The Consumer Staples and Health Care sectors were the largest contributors to relative performance. Regarding individual positions, Nintendo Co., Ltd., Coca-Cola HBC AG, Heidelberg Materials AG, CaixaBank SA, and 3i Group Plc were the top five contributors to absolute performance.

Detractors from Performance

Industrials and Consumer Discretionary sectors were the largest detractors from relative performance. Regarding individual positions, Meituan, Taiwan Semiconductor Manufacturing Co., Ltd., PT Bank Central Asia Tbk, Nippon Sanso Holdings Corp., and Intermediate Capital Group Plc were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Corporate Governance Reforms in Japan	Positive	Ongoing pressure from the Tokyo Stock Exchange to prioritize shareholder returns spurred a wave of share-buyback announcements, signaling a durable shift toward shareholder-friendly capital allocation and supporting valuations across Japan’s equity market.
Germany’s Post-Election Fiscal Stimulus	Positive	Following Germany's February 2025 federal election, coalition leaders agreed to loosen constitutional debt restrictions, create a €500 billion infrastructure fund, and increase defense expenditures—measures anticipated to boost domestic growth and support broader European equities.
Aggressive Reciprocal Tariffs	Negative	Broad reciprocal tariffs introduced by the U.S. in early April 2025 triggered retaliatory threats; the E.U. and China quickly prepared counter measures, reviving fears of a wider trade war and clouding the outlook for export-oriented economies. This uncertainty also caused the U.S. dollar (USD) to weaken against major currencies like the Euro, negatively impacting international companies earning profits in USD, as these profits became less valuable when converted to their home currencies.
China’s Ongoing Property Sector Weakness	Negative	China's property sector remained weak in early 2025, evidenced by contracting investment and home sales, negatively influencing growth expectations and investor sentiment toward equities with mainland exposure.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed ten semi-annual periods of Class A shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger International Opportunities Fund Class A	8.07%	8.93%	4.22%
Alger International Opportunities Fund Class A—excluding sales load	14.05%	10.11%	4.78%
MSCI ACWI ex USA	12.52%	10.63%	5.34%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 152,911,850

Holdings Count | Holding

^[2]

Investment Company Portfolio Turnover

47.88%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$152,911,850
Total number of portfolio holdings¹	41
Portfolio turnover rate	47.88%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Country Allocation} ^†

Belgium	1.9%
Brazil	3.8%
Canada	7.4%
China	5.1%
France	9.5%
Germany	9.4%
India	5.5%
Indonesia	2.0%
Italy	1.5%
Japan	15.6%
Mexico	2.5%
Norway	1.6%
Saudi Arabia	1.9%
South Korea	1.7%
Spain	2.9%
Switzerland	3.2%
Taiwan	4.0%
United Kingdom	15.8%
Short-Term Investments and Net Other Assets	4.7%
	100.0%

^†	Based on net assets.

C000024901 [Member]

Shareholder Report [Line Items]

Fund Name

Alger International Opportunities Fund

Class Name

Class B

Trading Symbol

AFGPX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger International Opportunities Fund (Class B / AFGPX)	$65	1.27%(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 65

Expense Ratio, Percent

1.27%

^[3]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger International Opportunities Fund Class B returned a 5.24% return for the fiscal six-month period ended April 30, 2025, compared to the 6.21% return of the MSCI ACWI ex USA. During the reporting period, the largest sector weightings were Financials and Industrials. The largest sector overweight was Consumer Discretionary and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Corporate Governance Reforms in Japan	Positive	Ongoing pressure from the Tokyo Stock Exchange to prioritize shareholder returns spurred a wave of share-buyback announcements, signaling a durable shift toward shareholder-friendly capital allocation and supporting valuations across Japan’s equity market.
Germany’s Post-Election Fiscal Stimulus	Positive	Following Germany's February 2025 federal election, coalition leaders agreed to loosen constitutional debt restrictions, create a €500 billion infrastructure fund, and increase defense expenditures—measures anticipated to boost domestic growth and support broader European equities.
Aggressive Reciprocal Tariffs	Negative	Broad reciprocal tariffs introduced by the U.S. in early April 2025 triggered retaliatory threats; the E.U. and China quickly prepared counter measures, reviving fears of a wider trade war and clouding the outlook for export-oriented economies. This uncertainty also caused the U.S. dollar (USD) to weaken against major currencies like the Euro, negatively impacting international companies earning profits in USD, as these profits became less valuable when converted to their home currencies.
China’s Ongoing Property Sector Weakness	Negative	China's property sector remained weak in early 2025, evidenced by contracting investment and home sales, negatively influencing growth expectations and investor sentiment toward equities with mainland exposure.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed ten semi-annual periods of Class B shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger International Opportunities Fund Class B	10.09%	10.02%	4.53%
Alger International Opportunities Fund Class B—excluding contingent deferred sales charges	14.09%	10.15%	4.53%
MSCI ACWI ex USA	12.52%	10.63%	5.34%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 152,911,850

Holdings Count | Holding

^[4]

Investment Company Portfolio Turnover

47.88%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$152,911,850
Total number of portfolio holdings¹	41
Portfolio turnover rate	47.88%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Country Allocation} ^†

Belgium	1.9%
Brazil	3.8%
Canada	7.4%
China	5.1%
France	9.5%
Germany	9.4%
India	5.5%
Indonesia	2.0%
Italy	1.5%
Japan	15.6%
Mexico	2.5%
Norway	1.6%
Saudi Arabia	1.9%
South Korea	1.7%
Spain	2.9%
Switzerland	3.2%
Taiwan	4.0%
United Kingdom	15.8%
Short-Term Investments and Net Other Assets	4.7%
	100.0%

^†	Based on net assets.

C000024902 [Member]

Shareholder Report [Line Items]

Fund Name

Alger International Opportunities Fund

Class Name

Class C

Trading Symbol

ALGCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger International Opportunities Fund (Class C / ALGCX)	$108	2.12%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 108

Expense Ratio, Percent

2.12%

^[5]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger International Opportunities Fund Class C returned a 4.78%, excluding contingent deferred sales charge, return for the fiscal six-month period ended April 30, 2025, compared to the 6.21% return of the MSCI ACWI ex USA. During the reporting period, the largest sector weightings were Financials and Industrials. The largest sector overweight was Consumer Discretionary and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Corporate Governance Reforms in Japan	Positive	Ongoing pressure from the Tokyo Stock Exchange to prioritize shareholder returns spurred a wave of share-buyback announcements, signaling a durable shift toward shareholder-friendly capital allocation and supporting valuations across Japan’s equity market.
Germany’s Post-Election Fiscal Stimulus	Positive	Following Germany's February 2025 federal election, coalition leaders agreed to loosen constitutional debt restrictions, create a €500 billion infrastructure fund, and increase defense expenditures—measures anticipated to boost domestic growth and support broader European equities.
Aggressive Reciprocal Tariffs	Negative	Broad reciprocal tariffs introduced by the U.S. in early April 2025 triggered retaliatory threats; the E.U. and China quickly prepared counter measures, reviving fears of a wider trade war and clouding the outlook for export-oriented economies. This uncertainty also caused the U.S. dollar (USD) to weaken against major currencies like the Euro, negatively impacting international companies earning profits in USD, as these profits became less valuable when converted to their home currencies.
China’s Ongoing Property Sector Weakness	Negative	China's property sector remained weak in early 2025, evidenced by contracting investment and home sales, negatively influencing growth expectations and investor sentiment toward equities with mainland exposure.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed ten semi-annual periods of Class C shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger International Opportunities Fund Class C	12.49%	9.26%	4.12%
Alger International Opportunities Fund Class C—excluding contingent deferred sales charges	13.49%	9.26%	4.12%
MSCI ACWI ex USA	12.52%	10.63%	5.34%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 152,911,850

Holdings Count | Holding

^[6]

Investment Company Portfolio Turnover

47.88%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$152,911,850
Total number of portfolio holdings¹	41
Portfolio turnover rate	47.88%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Country Allocation} ^†

Belgium	1.9%
Brazil	3.8%
Canada	7.4%
China	5.1%
France	9.5%
Germany	9.4%
India	5.5%
Indonesia	2.0%
Italy	1.5%
Japan	15.6%
Mexico	2.5%
Norway	1.6%
Saudi Arabia	1.9%
South Korea	1.7%
Spain	2.9%
Switzerland	3.2%
Taiwan	4.0%
United Kingdom	15.8%
Short-Term Investments and Net Other Assets	4.7%
	100.0%

^†	Based on net assets.

C000039971 [Member]

Shareholder Report [Line Items]

Fund Name

Alger International Opportunities Fund

Class Name

Class I

Trading Symbol

AIGIX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger International Opportunities Fund (Class I / AIGIX)	$65	1.27%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 65

Expense Ratio, Percent

1.27%

^[7]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger International Opportunities Fund Class I returned a 5.21% return for the fiscal six-month period ended April 30, 2025, compared to the 6.21% return of the MSCI ACWI ex USA. During the reporting period, the largest sector weightings were Financials and Industrials. The largest sector overweight was Consumer Discretionary and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Corporate Governance Reforms in Japan	Positive	Ongoing pressure from the Tokyo Stock Exchange to prioritize shareholder returns spurred a wave of share-buyback announcements, signaling a durable shift toward shareholder-friendly capital allocation and supporting valuations across Japan’s equity market.
Germany’s Post-Election Fiscal Stimulus	Positive	Following Germany's February 2025 federal election, coalition leaders agreed to loosen constitutional debt restrictions, create a €500 billion infrastructure fund, and increase defense expenditures—measures anticipated to boost domestic growth and support broader European equities.
Aggressive Reciprocal Tariffs	Negative	Broad reciprocal tariffs introduced by the U.S. in early April 2025 triggered retaliatory threats; the E.U. and China quickly prepared counter measures, reviving fears of a wider trade war and clouding the outlook for export-oriented economies. This uncertainty also caused the U.S. dollar (USD) to weaken against major currencies like the Euro, negatively impacting international companies earning profits in USD, as these profits became less valuable when converted to their home currencies.
China’s Ongoing Property Sector Weakness	Negative	China's property sector remained weak in early 2025, evidenced by contracting investment and home sales, negatively influencing growth expectations and investor sentiment toward equities with mainland exposure.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed ten semi-annual periods of Class I shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger International Opportunities Fund Class I	14.11%	10.14%	4.91%
MSCI ACWI ex USA	12.52%	10.63%	5.34%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 152,911,850

Holdings Count | Holding

^[8]

Investment Company Portfolio Turnover

47.88%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$152,911,850
Total number of portfolio holdings¹	41
Portfolio turnover rate	47.88%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Country Allocation} ^†

Belgium	1.9%
Brazil	3.8%
Canada	7.4%
China	5.1%
France	9.5%
Germany	9.4%
India	5.5%
Indonesia	2.0%
Italy	1.5%
Japan	15.6%
Mexico	2.5%
Norway	1.6%
Saudi Arabia	1.9%
South Korea	1.7%
Spain	2.9%
Switzerland	3.2%
Taiwan	4.0%
United Kingdom	15.8%
Short-Term Investments and Net Other Assets	4.7%
	100.0%

^†	Based on net assets.

C000095957 [Member]

Shareholder Report [Line Items]

Fund Name

Alger International Opportunities Fund

Class Name

Class Z

Trading Symbol

ALCZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger International Opportunities Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger International Opportunities Fund (Class Z / ALCZX)	$44	0.86%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 44

Expense Ratio, Percent

0.86%

^[9]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger International Opportunities Fund Class Z returned a 5.42% return for the fiscal six-month period ended April 30, 2025, compared to the 6.21% return of the MSCI ACWI ex USA. During the reporting period, the largest sector weightings were Financials and Industrials. The largest sector overweight was Consumer Discretionary and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Corporate Governance Reforms in Japan	Positive	Ongoing pressure from the Tokyo Stock Exchange to prioritize shareholder returns spurred a wave of share-buyback announcements, signaling a durable shift toward shareholder-friendly capital allocation and supporting valuations across Japan’s equity market.
Germany’s Post-Election Fiscal Stimulus	Positive	Following Germany's February 2025 federal election, coalition leaders agreed to loosen constitutional debt restrictions, create a €500 billion infrastructure fund, and increase defense expenditures—measures anticipated to boost domestic growth and support broader European equities.
Aggressive Reciprocal Tariffs	Negative	Broad reciprocal tariffs introduced by the U.S. in early April 2025 triggered retaliatory threats; the E.U. and China quickly prepared counter measures, reviving fears of a wider trade war and clouding the outlook for export-oriented economies. This uncertainty also caused the U.S. dollar (USD) to weaken against major currencies like the Euro, negatively impacting international companies earning profits in USD, as these profits became less valuable when converted to their home currencies.
China’s Ongoing Property Sector Weakness	Negative	China's property sector remained weak in early 2025, evidenced by contracting investment and home sales, negatively influencing growth expectations and investor sentiment toward equities with mainland exposure.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed ten semi-annual periods of Class Z shares of the Fund. The graph assumes a $500,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index for the same period.

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger International Opportunities Fund Class Z	14.52%	10.55%	5.24%
MSCI ACWI ex USA	12.52%	10.63%	5.34%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 152,911,850

Holdings Count | Holding

^[10]

Investment Company Portfolio Turnover

47.88%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$152,911,850
Total number of portfolio holdings¹	41
Portfolio turnover rate	47.88%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Country Allocation} ^†

Belgium	1.9%
Brazil	3.8%
Canada	7.4%
China	5.1%
France	9.5%
Germany	9.4%
India	5.5%
Indonesia	2.0%
Italy	1.5%
Japan	15.6%
Mexico	2.5%
Norway	1.6%
Saudi Arabia	1.9%
South Korea	1.7%
Spain	2.9%
Switzerland	3.2%
Taiwan	4.0%
United Kingdom	15.8%
Short-Term Investments and Net Other Assets	4.7%
	100.0%

^†	Based on net assets.

C000024903 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Growth Fund

Class Name

Class A

Trading Symbol

ALSAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Growth Fund (Class A / ALSAX)	$60	1.32%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 60

Expense Ratio, Percent

1.32%

^[11]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Growth Fund Class A returned -15.48%, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Health Care. The largest sector overweight was Information Technology and the largest sector underweight was Industrials.

Contributors to Performance

The Industrials and Consumer Staples sectors were the largest contributors to relative performance. Regarding individual positions, Guardant Health, Inc., Aritzia, Inc., Oddity Tech Ltd., Xometry, Inc., and Duolingo, Inc. were the top five contributors to absolute performance.

Detractors from Performance

The Consumer Discretionary and Information Technology sectors were the largest detractors from relative performance. Regarding individual positions, Impulse Dynamics Plc, Aritzia, Inc., Bio-Techne Corp., RH, and Shake Shack, Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Growth Fund Class A	(13.52)%	(1.60)%	4.89%
Alger Small Cap Growth Fund Class A—excluding sales load	(8.73)%	(0.54)%	5.46%
Russell 2000 Growth Index	2.42%	0.00%	6.39%
S&P 500 Index	12.10%	0.00%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 176,836,329

Holdings Count | Holding

102

^[12]

Investment Company Portfolio Turnover

18.11%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$176,836,329
Total number of portfolio holdings¹	102
Portfolio turnover rate	18.11%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	0.7%
Consumer Discretionary	15.8%
Consumer Staples	3.0%
Energy	0.9%
Financials	2.8%
Health Care	28.8%
Industrials	16.9%
Information Technology	29.4%
Materials	0.1%
Utilities	0.5%
Short-Term Investments and Other Net Assets	1.1%
	100.0%

^†	Based on net assets.

C000024904 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Growth Fund

Class Name

Class B

Trading Symbol

ALSCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Growth Fund (Class B / ALSCX)	$50	1.09%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 50

Expense Ratio, Percent

1.09%

^[13]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Growth Fund Class B returned -15.40% for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Health Care. The largest sector overweight was Information Technology and the largest sector underweight was Industrials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Growth Fund Class B	(12.22)%	(0.71)%	5.10%
Alger Small Cap Growth Fund Class B—excluding contingent deferred sales charges	(8.56)%	(0.54)%	5.10%
Russell 2000 Growth Index	2.42%	0.00%	6.39%
S&P 500 Index	12.10%	0.00%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 176,836,329

Holdings Count | Holding

102

^[14]

Investment Company Portfolio Turnover

18.11%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$176,836,329
Total number of portfolio holdings¹	102
Portfolio turnover rate	18.11%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	0.7%
Consumer Discretionary	15.8%
Consumer Staples	3.0%
Energy	0.9%
Financials	2.8%
Health Care	28.8%
Industrials	16.9%
Information Technology	29.4%
Materials	0.1%
Utilities	0.5%
Short-Term Investments and Other Net Assets	1.1%
	100.0%

^†	Based on net assets.

C000024905 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Growth Fund

Class Name

Class C

Trading Symbol

AGSCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Growth Fund (Class C / AGSCX)	$97	2.12%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 97

Expense Ratio, Percent

2.12%

^[15]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Growth Fund Class C returned -15.76%, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Health Care. The largest sector overweight was Information Technology and the largest sector underweight was Industrials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Growth Fund Class C	(10.25)%	(1.31)%	4.78%
Alger Small Cap Growth Fund Class C—excluding contingent deferred sales charges	(9.34)%	(1.31)%	4.78%
Russell 2000 Growth Index	2.42%	0.00%	6.39%
S&P 500 Index	12.10%	0.00%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 176,836,329

Holdings Count | Holding

102

^[16]

Investment Company Portfolio Turnover

18.11%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$176,836,329
Total number of portfolio holdings¹	102
Portfolio turnover rate	18.11%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	0.7%
Consumer Discretionary	15.8%
Consumer Staples	3.0%
Energy	0.9%
Financials	2.8%
Health Care	28.8%
Industrials	16.9%
Information Technology	29.4%
Materials	0.1%
Utilities	0.5%
Short-Term Investments and Other Net Assets	1.1%
	100.0%

^†	Based on net assets.

C000095958 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Growth Fund

Class Name

Class Y

Trading Symbol

ASCYX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Growth Fund (Class Y / ASCYX)	$39	0.85%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 39

Expense Ratio, Percent

0.85%

^[17]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Growth Fund Class Y returned -15.21% for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Health Care. The largest sector overweight was Information Technology and the largest sector underweight was Industrials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed semi-annual periods for the life of Class Y shares of the Fund. The graph assumes a $500,000 initial investment at net asset value at the inception date of the Fund in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 12/31/21
Alger Small Cap Growth Fund Class Y	(8.28)%	(11.73)%
Russell 2000 Growth Index	2.42%	(3.48)%
S&P 500 Index	12.10%	6.40%

Performance Inception Date

Dec. 31, 2021

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 176,836,329

Holdings Count | Holding

102

^[18]

Investment Company Portfolio Turnover

18.11%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$176,836,329
Total number of portfolio holdings¹	102
Portfolio turnover rate	18.11%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	0.7%
Consumer Discretionary	15.8%
Consumer Staples	3.0%
Energy	0.9%
Financials	2.8%
Health Care	28.8%
Industrials	16.9%
Information Technology	29.4%
Materials	0.1%
Utilities	0.5%
Short-Term Investments and Other Net Assets	1.1%
	100.0%

^†	Based on net assets.

C000232602 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Growth Fund

Class Name

Class Z

Trading Symbol

ASCZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Growth Fund (Class Z / ASCZX)	$46	1.00%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 46

Expense Ratio, Percent

1.00%

^[19]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Growth Fund Class Z returned -15.33% for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Health Care. The largest sector overweight was Information Technology and the largest sector underweight was Industrials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Growth Fund Class Z	(8.39)%	(0.22)%	5.83%
Russell 2000 Growth Index	2.42%	0.00%	6.39%
S&P 500 Index	12.10%	0.00%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 176,836,329

Holdings Count | Holding

102

^[20]

Investment Company Portfolio Turnover

18.11%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$176,836,329
Total number of portfolio holdings¹	102
Portfolio turnover rate	18.11%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	0.7%
Consumer Discretionary	15.8%
Consumer Staples	3.0%
Energy	0.9%
Financials	2.8%
Health Care	28.8%
Industrials	16.9%
Information Technology	29.4%
Materials	0.1%
Utilities	0.5%
Short-Term Investments and Other Net Assets	1.1%
	100.0%

^†	Based on net assets.

C000024906 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Growth & Income Fund

Class Name

Class A

Trading Symbol

ALBAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Growth & Income Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Growth & Income Fund (Class A / ALBAX)	$45	0.91%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 45

Expense Ratio, Percent

0.91%

^[21]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Growth & Income Fund Class A returned -2.05%, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Financials. The largest sector overweight was Energy and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

The Information Technology and Real Estate sectors were the largest contributors to relative performance. Regarding individual positions, Broadcom Inc., JPMorgan Chase & Co., Visa Inc., KLA Corp., and CME Group Inc. were the top five contributors to absolute performance.

Detractors from Performance

The Consumer Discretionary and Financials sectors were the largest detractors from relative performance. Regarding individual positions, UnitedHealth Group Inc., Apple Inc., Blackstone Inc., Alphabet Inc., and PepsiCo, Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Growth & Income Fund Class A	4.60%	14.19%	10.99%
Alger Growth & Income Fund Class A—excluding sales load	10.40%	15.43%	11.59%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 659,545,058

Holdings Count | Holding

^[22]

Investment Company Portfolio Turnover

1.50%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$659,545,058
Total number of portfolio holdings¹	77
Portfolio turnover rate	1.50%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	9.3%
Consumer Discretionary	7.3%
Consumer Staples	6.3%
Energy	4.5%
Financials	14.2%
Health Care	11.7%
Industrials	6.0%
Information Technology	29.6%
Materials	1.4%
Real Estate	3.2%
Utilities	1.5%
Short-Term Investments and Other Net Assets	5.0%
	100.0%

^†	Based on net assets.

C000024908 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Growth & Income Fund

Class Name

Class C

Trading Symbol

ALBCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Growth & Income Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Growth & Income Fund (Class C / ALBCX)	$81	1.66%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 81

Expense Ratio, Percent

1.66%

^[23]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Growth & Income Fund Class C returned -2.41%, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Financials. The largest sector overweight was Energy and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Growth & Income Fund Class C	8.56%	14.57%	10.92%
Alger Growth & Income Fund Class C—excluding contingent deferred sales charges	9.56%	14.57%	10.92%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 659,545,058

Holdings Count | Holding

^[24]

Investment Company Portfolio Turnover

1.50%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$659,545,058
Total number of portfolio holdings¹	77
Portfolio turnover rate	1.50%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	9.3%
Consumer Discretionary	7.3%
Consumer Staples	6.3%
Energy	4.5%
Financials	14.2%
Health Care	11.7%
Industrials	6.0%
Information Technology	29.6%
Materials	1.4%
Real Estate	3.2%
Utilities	1.5%
Short-Term Investments and Other Net Assets	5.0%
	100.0%

^†	Based on net assets.

C000111113 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Growth & Income Fund

Class Name

Class Z

Trading Symbol

AGIZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Growth & Income Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Growth & Income Fund (Class Z / AGIZX)	$29	0.60%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 29

Expense Ratio, Percent

0.60%

^[25]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Growth & Income Fund Class Z returned -1.90% for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Financials. The largest sector overweight was Energy and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Growth & Income Fund Class Z	10.74%	15.80%	11.95%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 659,545,058

Holdings Count | Holding

^[26]

Investment Company Portfolio Turnover

1.50%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$659,545,058
Total number of portfolio holdings¹	77
Portfolio turnover rate	1.50%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	9.3%
Consumer Discretionary	7.3%
Consumer Staples	6.3%
Energy	4.5%
Financials	14.2%
Health Care	11.7%
Industrials	6.0%
Information Technology	29.6%
Materials	1.4%
Real Estate	3.2%
Utilities	1.5%
Short-Term Investments and Other Net Assets	5.0%
	100.0%

^†	Based on net assets.

C000024909 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Growth Fund

Class Name

Class A

Trading Symbol

AMGAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Growth Fund (Class A / AMGAX)	$60	1.22%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 60

Expense Ratio, Percent

1.22%

^[27]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Growth Fund Class A returned -2.32%, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Industrials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

The Communication Services and Materials sectors were the largest contributors to relative performance. Regarding individual positions, Palantir Technologies Inc., Spotify Technology SA, AppLovin Corp., GFL Environmental Inc., and Constellation Software Inc. were the top five contributors to absolute performance.

Detractors from Performance

The Industrials and Health Care sectors were the largest detractors from relative performance. Regarding individual positions, Globant SA, e.l.f. Beauty, Inc., Vaxcyte, Inc., Marvell Technology, Inc., and Pinterest, Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Mid Cap Growth Fund Class A	0.35%	8.58%	8.12%
Alger Mid Cap Growth Fund Class A—excluding sales load	5.91%	9.76%	8.71%
Russell Midcap Growth Index	13.65%	12.31%	10.58%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 226,126,519

Holdings Count | Holding

^[28]

Investment Company Portfolio Turnover

44.51%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$226,126,519
Total number of portfolio holdings¹	62
Portfolio turnover rate	44.51%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	6.8%
Consumer Discretionary	8.9%
Consumer Staples	0.5%
Financials	11.1%
Health Care	7.3%
Industrials	22.0%
Information Technology	28.8%
Materials	1.4%
Real Estate	4.3%
Utilities	3.1%
Short-Term Investments and Other Net Assets	5.8%
	100.0%

^†	Based on net assets.

C000024910 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Growth Fund

Class Name

Class B

Trading Symbol

AMCGX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Growth Fund (Class B / AMCGX)	$67	1.36%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 67

Expense Ratio, Percent

1.36%

^[29]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Growth Fund Class B returned -2.40% for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Industrials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Mid Cap Growth Fund Class B	1.79%	9.60%	8.41%
Alger Mid Cap Growth Fund Class B—excluding contingent deferred sales charges	5.79%	9.72%	8.41%
Russell Midcap Growth Index	13.65%	12.31%	10.58%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 226,126,519

Holdings Count | Holding

^[30]

Investment Company Portfolio Turnover

44.51%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$226,126,519
Total number of portfolio holdings¹	62
Portfolio turnover rate	44.51%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	6.8%
Consumer Discretionary	8.9%
Consumer Staples	0.5%
Financials	11.1%
Health Care	7.3%
Industrials	22.0%
Information Technology	28.8%
Materials	1.4%
Real Estate	4.3%
Utilities	3.1%
Short-Term Investments and Other Net Assets	5.8%
	100.0%

^†	Based on net assets.

C000024911 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Growth Fund

Class Name

Class C

Trading Symbol

AMGCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Growth Fund (Class C / AMGCX)	$100	2.04%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 100

Expense Ratio, Percent

2.04%

^[31]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Growth Fund Class C returned -2.72%, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Industrials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Mid Cap Growth Fund Class C	4.11%	8.88%	8.00%
Alger Mid Cap Growth Fund Class C—excluding contingent deferred sales charges	5.11%	8.88%	8.00%
Russell Midcap Growth Index	13.65%	12.31%	10.58%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 226,126,519

Holdings Count | Holding

^[32]

Investment Company Portfolio Turnover

44.51%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$226,126,519
Total number of portfolio holdings¹	62
Portfolio turnover rate	44.51%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	6.8%
Consumer Discretionary	8.9%
Consumer Staples	0.5%
Financials	11.1%
Health Care	7.3%
Industrials	22.0%
Information Technology	28.8%
Materials	1.4%
Real Estate	4.3%
Utilities	3.1%
Short-Term Investments and Other Net Assets	5.8%
	100.0%

^†	Based on net assets.

C000156504 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Growth Fund

Class Name

Class Z

Trading Symbol

AMCZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Growth Fund (Class Z / AMCZX)	$45	0.91%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 45

Expense Ratio, Percent

0.91%

^[33]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Growth Fund Class Z returned -2.17% for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Industrials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed semi-annual periods for the life of Class Z shares of the Fund. The graph assumes a $500,000 initial investment at net asset value at the inception date of the Fund in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	Since Inception 5/28/15
Alger Mid Cap Growth Fund Class Z	6.20%	10.09%	8.68%
Russell Midcap Growth Index	13.65%	12.31%	10.47%
S&P 500 Index	12.10%	15.61%	12.20%

Performance Inception Date

May 28, 2015

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 226,126,519

Holdings Count | Holding

^[34]

Investment Company Portfolio Turnover

44.51%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$226,126,519
Total number of portfolio holdings¹	62
Portfolio turnover rate	44.51%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	6.8%
Consumer Discretionary	8.9%
Consumer Staples	0.5%
Financials	11.1%
Health Care	7.3%
Industrials	22.0%
Information Technology	28.8%
Materials	1.4%
Real Estate	4.3%
Utilities	3.1%
Short-Term Investments and Other Net Assets	5.8%
	100.0%

^†	Based on net assets.

C000024912 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Capital Appreciation Fund

Class Name

Class A

Trading Symbol

ACAAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Capital Appreciation Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Capital Appreciation Fund (Class A / ACAAX)	$63	1.27%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 63

Expense Ratio, Percent

1.27%

^[35]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Capital Appreciation Fund Class A returned -0.83%, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Communication Services. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

The Communication Services and Financials sectors were the largest contributors to relative performance. Regarding individual positions, AppLovin Corp., Netflix, Inc., Natera, Inc., Spotify Technology SA, and GFL Environmental Inc. were the top five contributors to absolute performance.

Detractors from Performance

The Consumer Discretionary and Consumer Staples sectors were the largest detractors from relative performance. Regarding individual positions, NVIDIA Corp., Apple Inc., Meta Platforms Inc, Taiwan Semiconductor Manufacturing Co., Ltd., and United Airlines Holdings, Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Capital Appreciation Fund Class A	14.33%	13.53%	12.97%
Alger Capital Appreciation Fund Class A—excluding sales load	20.66%	14.76%	13.59%
Russell 1000 Growth Index	14.53%	17.23%	15.27%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 1,794,238,201

Holdings Count | Holding

^[36]

Investment Company Portfolio Turnover

44.42%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$1,794,238,201
Total number of portfolio holdings¹	74
Portfolio turnover rate	44.42%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.8%
Consumer Discretionary	13.2%
Consumer Staples	0.2%
Energy	0.2%
Financials	5.8%
Health Care	6.6%
Industrials	6.7%
Information Technology	46.9%
Materials	0.1%
Utilities	3.6%
Short-Term Investments and Other Net Assets	(0.1)%
	100.0%

^†	Based on net assets.

C000024914 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Capital Appreciation Fund

Class Name

Class C

Trading Symbol

ALCCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Capital Appreciation Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Capital Appreciation Fund (Class C / ALCCX)	$101	2.04%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 101

Expense Ratio, Percent

2.04%

^[37]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Capital Appreciation Fund Class C returned -1.14%, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Communication Services. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Capital Appreciation Fund Class C	18.91%	13.92%	12.90%
Alger Capital Appreciation Fund Class C—excluding contingent deferred sales charges	19.87%	13.92%	12.90%
Russell 1000 Growth Index	14.53%	17.23%	15.27%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 1,794,238,201

Holdings Count | Holding

^[38]

Investment Company Portfolio Turnover

44.42%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$1,794,238,201
Total number of portfolio holdings¹	74
Portfolio turnover rate	44.42%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.8%
Consumer Discretionary	13.2%
Consumer Staples	0.2%
Energy	0.2%
Financials	5.8%
Health Care	6.6%
Industrials	6.7%
Information Technology	46.9%
Materials	0.1%
Utilities	3.6%
Short-Term Investments and Other Net Assets	(0.1)%
	100.0%

^†	Based on net assets.

C000095959 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Capital Appreciation Fund

Class Name

Class Z

Trading Symbol

ACAZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Capital Appreciation Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Capital Appreciation Fund (Class Z / ACAZX)	$45	0.91%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 45

Expense Ratio, Percent

0.91%

^[39]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Capital Appreciation Fund Class Z returned -0.62% for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Communication Services. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Capital Appreciation Fund Class Z	21.11%	15.18%	13.99%
Russell 1000 Growth Index	14.53%	17.23%	15.27%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 1,794,238,201

Holdings Count | Holding

^[40]

Investment Company Portfolio Turnover

44.42%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$1,794,238,201
Total number of portfolio holdings¹	74
Portfolio turnover rate	44.42%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.8%
Consumer Discretionary	13.2%
Consumer Staples	0.2%
Energy	0.2%
Financials	5.8%
Health Care	6.6%
Industrials	6.7%
Information Technology	46.9%
Materials	0.1%
Utilities	3.6%
Short-Term Investments and Other Net Assets	(0.1)%
	100.0%

^†	Based on net assets.

C000024915 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Health Sciences Fund

Class Name

Class A

Trading Symbol

AHSAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Health Sciences Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Health Sciences Fund (Class A / AHSAX)	$52	1.14%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 52

Expense Ratio, Percent

1.14%

^[41]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Health Sciences Fund Class A returned -14.51%, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the 1.74% return of the S&P 500 Index and the -5.42% return of the Russell 3000 Health Care Index.

Contributors to Performance

Regarding individual positions, McKesson Corp. Boston Scientific Corp., Cardinal Health, Inc., Quest Diagnostics, Inc. and Inari Medical, Inc. were the top five contributors to absolute performance.

Detractors from Performance

Regarding individual positions, Impulse Dyanamics Plc., UnitedHealth Group, Inc., Amgen Inc., Biogen Inc., and Glaukos Corp. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Health Sciences Fund Class A	(16.89)%	(1.69)%	4.29%
Alger Health Sciences Fund Class A—excluding sales load	(12.28)%	(0.63)%	4.86%
Russell 3000 Healthcare Index	1.08%	7.43%	8.23%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 68,552,010

Holdings Count | Holding

^[42]

Investment Company Portfolio Turnover

130.52%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$68,552,010
Total number of portfolio holdings¹	40
Portfolio turnover rate	130.52%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Financials	0.6%
Health Care	88.3%
Real Estate	7.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000024917 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Health Sciences Fund

Class Name

Class C

Trading Symbol

AHSCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Health Sciences Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Health Sciences Fund (Class C / AHSCX)	$90	1.95%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 90

Expense Ratio, Percent

1.95%

^[43]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Health Sciences Fund Class C returned -14.81%, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the 1.74% return of the S&P 500 Index and the -5.42% return of the Russell 3000 Health Care Index.

Contributors to Performance

Regarding individual positions, McKesson Corp. Boston Scientific Corp., Cardinal Health, Inc., Quest Diagnostics, Inc. and Inari Medical, Inc. were the top five contributors to absolute performance.

Detractors from Performance

Regarding individual positions, Impulse Dyanamics Plc., UnitedHealth Group, Inc., Amgen Inc., Biogen Inc., and Glaukos Corp. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Health Sciences Fund Class C	(13.66)%	(1.38)%	4.21%
Alger Health Sciences Fund Class C—excluding contingent deferred sales charges	(12.79)%	(1.38)%	4.21%
Russell 3000 Healthcare Index	1.08%	7.43%	8.23%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 68,552,010

Holdings Count | Holding

^[44]

Investment Company Portfolio Turnover

130.52%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$68,552,010
Total number of portfolio holdings¹	40
Portfolio turnover rate	130.52%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Financials	0.6%
Health Care	88.3%
Real Estate	7.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000156505 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Health Sciences Fund

Class Name

Class Z

Trading Symbol

AHSZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Health Sciences Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Health Sciences Fund (Class Z / AHSZX)	$35	0.76%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 35

Expense Ratio, Percent

0.76%

^[45]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Health Sciences Fund Class Z returned -14.32% for the fiscal six-month period ended April 30, 2025, compared to the 1.74% return of the S&P 500 Index and the -5.42% return of the Russell 3000 Health Care Index.

Contributors to Performance

Regarding individual positions, McKesson Corp. Boston Scientific Corp., Cardinal Health, Inc., Quest Diagnostics, Inc. and Inari Medical, Inc. were the top five contributors to absolute performance.

Detractors from Performance

Regarding individual positions, Impulse Dyanamics Plc., UnitedHealth Group, Inc., Amgen Inc., Biogen Inc., and Glaukos Corp. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	Since Inception 5/28/15
Alger Health Sciences Fund Class Z	(11.98)%	(0.27)%	4.30%
Russell 3000 Healthcare Index	1.08%	7.43%	7.73%
S&P 500 Index	12.10%	15.61%	12.20%

Performance Inception Date

May 28, 2015

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 68,552,010

Holdings Count | Holding

^[46]

Investment Company Portfolio Turnover

130.52%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$68,552,010
Total number of portfolio holdings¹	40
Portfolio turnover rate	130.52%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Financials	0.6%
Health Care	88.3%
Real Estate	7.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000024918 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Weatherbie Specialized Growth Fund

Class Name

Class A

Trading Symbol

ALMAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Weatherbie Specialized Growth Fund (Class A / ALMAX)	$61	1.29%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 61

Expense Ratio, Percent

1.29%

^[47]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Weatherbie Specialized Growth Fund Class A generated a -9.88% return, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the -8.70% return of the Russell 2500 Growth Index. During the reporting period, the largest sector weightings were Health Care and Industrials. The largest sector overweight was Financials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

The Consumer Discretionary and Materials sectors were the largest contributors to relative performance. Regarding individual positions, Natera, Inc., Casella Waste Systems, Inc., Palomar Holdings, Inc., Kratos Defense & Security Solutions, Inc., and Progyny, Inc. were the top five contributors to absolute performance.

Detractors from Performance

The Health Care and Financials sectors were the largest detractors from relative performance. Regarding individual positions, Neogen Corp, RXO, Inc., Semtech Corp., Tandem Diabetes Care, Inc., and Montrose Environmental Group Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Weatherbie Specialized Growth Fund Class A	(7.31)%	1.18%	6.37%
Alger Weatherbie Specialized Growth Fund Class A—excluding sales load	(2.18)%	2.28%	6.94%
Russell 2500 Growth Index	0.84%	8.04%	7.63%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 342,387,744

Holdings Count | Holding

^[48]

Investment Company Portfolio Turnover

30.76%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$342,387,744
Total number of portfolio holdings¹	51
Portfolio turnover rate	30.76%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	9.3%
Energy	0.5%
Financials	13.2%
Health Care	21.9%
Industrials	31.4%
Information Technology	13.6%
Real Estate	6.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000024920 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Weatherbie Specialized Growth Fund

Class Name

Class C

Trading Symbol

ALMCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this informationby contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Weatherbie Specialized Growth Fund (Class C / ALMCX)	$97	2.07%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 97

Expense Ratio, Percent

2.07%

^[49]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Weatherbie Specialized Growth Fund Class C generated a -10.25% return, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the -8.70% return of the Russell 2500 Growth Index. During the reporting period, the largest sector weightings were Health Care and Industrials. The largest sector overweight was Financials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Weatherbie Specialized Growth Fund Class C	(3.94)%	1.52%	6.28%
Alger Weatherbie Specialized Growth Fund Class C—excluding contingent deferred sales charges	(2.96)%	1.52%	6.28%
Russell 2500 Growth Index	0.84%	8.04%	7.63%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 342,387,744

Holdings Count | Holding

^[50]

Investment Company Portfolio Turnover

30.76%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$342,387,744
Total number of portfolio holdings¹	51
Portfolio turnover rate	30.76%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	9.3%
Energy	0.5%
Financials	13.2%
Health Care	21.9%
Industrials	31.4%
Information Technology	13.6%
Real Estate	6.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000051550 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Weatherbie Specialized Growth Fund

Class Name

Class I

Trading Symbol

ASIMX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Weatherbie Specialized Growth Fund (Class I / ASIMX)	$63	1.34%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 63

Expense Ratio, Percent

1.34%

^[51]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Weatherbie Specialized Growth Fund Class I generated a -9.92% return for the fiscal six-month period ended April 30, 2025, compared to the -8.70% return of the Russell 2500 Growth Index. During the reporting period, the largest sector weightings were Health Care and Industrials. The largest sector overweight was Financials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Weatherbie Specialized Growth Fund Class I	(2.19)%	2.28%	6.94%
Russell 2500 Growth Index	0.84%	8.04%	7.63%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 342,387,744

Holdings Count | Holding

^[52]

Investment Company Portfolio Turnover

30.76%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$342,387,744
Total number of portfolio holdings¹	51
Portfolio turnover rate	30.76%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	9.3%
Energy	0.5%
Financials	13.2%
Health Care	21.9%
Industrials	31.4%
Information Technology	13.6%
Real Estate	6.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000095960 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Weatherbie Specialized Growth Fund

Class Name

Class Y

Trading Symbol

ASYMX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Weatherbie Specialized Growth Fund (Class Y / ASYMX)	$42	0.88%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 42

Expense Ratio, Percent

0.88%

^[53]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Weatherbie Specialized Growth Fund Class Y generated a -9.73% return for the fiscal six-month period ended April 30, 2025, compared to the -8.70% return of the Russell 2500 Growth Index. During the reporting period, the largest sector weightings were Health Care and Industrials. The largest sector overweight was Financials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	Since Inception 8/30/17
Alger Weatherbie Specialized Growth Fund Class Y	(1.88)%	2.68%	7.12%
Russell 2500 Growth Index	0.84%	8.04%	8.01%
S&P 500 Index	12.10%	15.61%	13.15%

Performance Inception Date

Aug. 30, 2017

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 342,387,744

Holdings Count | Holding

^[54]

Investment Company Portfolio Turnover

30.76%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$342,387,744
Total number of portfolio holdings¹	51
Portfolio turnover rate	30.76%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	9.3%
Energy	0.5%
Financials	13.2%
Health Care	21.9%
Industrials	31.4%
Information Technology	13.6%
Real Estate	6.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000193201 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Weatherbie Specialized Growth Fund

Class Name

Class Z

Trading Symbol

ASMZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Weatherbie Specialized Growth Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Weatherbie Specialized Growth Fund (Class Z / ASMZX)	$44	0.94%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 44

Expense Ratio, Percent

0.94%

^[55]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Weatherbie Specialized Growth Fund Class Z generated a -9.76% return for the fiscal six-month period ended April 30, 2025, compared to the -8.70% return of the Russell 2500 Growth Index. During the reporting period, the largest sector weightings were Health Care and Industrials. The largest sector overweight was Financials and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Weatherbie Specialized Growth Fund Class Z	(1.90)%	2.62%	7.30%
Russell 2500 Growth Index	0.84%	8.04%	7.63%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 342,387,744

Holdings Count | Holding

^[56]

Investment Company Portfolio Turnover

30.76%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$342,387,744
Total number of portfolio holdings¹	51
Portfolio turnover rate	30.76%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	9.3%
Energy	0.5%
Financials	13.2%
Health Care	21.9%
Industrials	31.4%
Information Technology	13.6%
Real Estate	6.1%
Short-Term Investments and Other Net Assets	4.0%
	100.0%

^†	Based on net assets.

C000059337 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Focus Fund

Class Name

Class A

Trading Symbol

AOFAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Focus Fund (Class A / AOFAX)	$60	1.29%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 60

Expense Ratio, Percent

1.29%

^[57]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Focus Fund Class A returned -11.93%, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Health Care and Information Technology. The largest sector overweight was Health Care and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

The Energy and Industrials sectors were the largest contributors to relative performance. Regarding individual positions, Natera, Inc., Inari Medical, Inc., Xometry, Inc., RBC Bearings, Inc., and Guidewire Software, Inc. were the top five contributors to absolute performance.

Detractors from Performance

The Health Care and Information Technology sectors were the largest detractors from relative performance. Regarding individual positions, FTAI Aviation Ltd., Upstart Holdings, Inc., Kura Sushi USA, Inc., Glaukos Corp. and Bio-Techne Corp. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Focus Fund Class A	(10.76)%	(4.95)%	4.31%
Alger Small Cap Focus Fund Class A—excluding sales load	(5.80)%	(3.91)%	4.87%
Russell 2000 Growth Index	2.42%	7.60%	6.39%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 857,810,298

Holdings Count | Holding

^[58]

Investment Company Portfolio Turnover

33.24%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$857,810,298
Total number of portfolio holdings¹	51
Portfolio turnover rate	33.24%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	3.7%
Financials	4.1%
Health Care	39.3%
Industrials	24.6%
Information Technology	18.7%
Utilities	3.0%
Short-Term Investments and Other Net Assets	6.6%
	100.0%

^†	Based on net assets.

C000059339 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Focus Fund

Class Name

Class C

Trading Symbol

AOFCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Focus Fund (Class C / AOFCX)	$93	1.99%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 93

Expense Ratio, Percent

1.99%

^[59]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Focus Fund Class C returned -12.26%, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Health Care and Information Technology. The largest sector overweight was Health Care and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Focus Fund Class C	(7.56)%	(4.55)%	4.29%
Alger Small Cap Focus Fund Class C—excluding contingent deferred sales charges	(6.63)%	(4.55)%	4.29%
Russell 2000 Growth Index	2.42%	7.60%	6.39%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 857,810,298

Holdings Count | Holding

^[60]

Investment Company Portfolio Turnover

33.24%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$857,810,298
Total number of portfolio holdings¹	51
Portfolio turnover rate	33.24%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	3.7%
Financials	4.1%
Health Care	39.3%
Industrials	24.6%
Information Technology	18.7%
Utilities	3.0%
Short-Term Investments and Other Net Assets	6.6%
	100.0%

^†	Based on net assets.

C000059340 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Focus Fund

Class Name

Class I

Trading Symbol

AOFIX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Focus Fund (Class I / AOFIX)	$56	1.21%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 56

Expense Ratio, Percent

1.21%

^[61]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Focus Fund Class I returned -11.91% for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Health Care and Information Technology. The largest sector overweight was Health Care and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Focus Fund Class I	(5.83)%	(3.80)%	4.96%
Russell 2000 Growth Index	2.42%	7.60%	6.39%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 857,810,298

Holdings Count | Holding

^[62]

Investment Company Portfolio Turnover

33.24%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$857,810,298
Total number of portfolio holdings¹	51
Portfolio turnover rate	33.24%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	3.7%
Financials	4.1%
Health Care	39.3%
Industrials	24.6%
Information Technology	18.7%
Utilities	3.0%
Short-Term Investments and Other Net Assets	6.6%
	100.0%

^†	Based on net assets.

C000095961 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Focus Fund

Class Name

Class Y

Trading Symbol

AOFYX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Focus Fund (Class Y / AOFYX)	$40	0.86%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 40

Expense Ratio, Percent

0.86%

^[63]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Focus Fund Class Y returned -11.74% for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Health Care and Information Technology. The largest sector overweight was Health Care and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	Since Inception 2/28/17
Alger Small Cap Focus Fund Class Y	(5.64)%	(3.49)%	4.97%
Russell 2000 Growth Index	2.42%	7.60%	6.58%
S&P 500 Index	12.10%	15.61%	12.97%

Performance Inception Date

Feb. 28, 2017

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 857,810,298

Holdings Count | Holding

^[64]

Investment Company Portfolio Turnover

33.24%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$857,810,298
Total number of portfolio holdings¹	51
Portfolio turnover rate	33.24%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	3.7%
Financials	4.1%
Health Care	39.3%
Industrials	24.6%
Information Technology	18.7%
Utilities	3.0%
Short-Term Investments and Other Net Assets	6.6%
	100.0%

^†	Based on net assets.

C000179520 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Small Cap Focus Fund

Class Name

Class Z

Trading Symbol

AGOZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Small Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Small Cap Focus Fund (Class Z / AGOZX)	$41	0.87%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 41

Expense Ratio, Percent

0.87%

^[65]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Small Cap Focus Fund Class Z returned -11.74% for the fiscal six-month period ended April 30, 2025, compared to the -8.97% return of the Russell 2000 Growth Index. During the reporting period, the largest sector weightings were Health Care and Information Technology. The largest sector overweight was Health Care and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	10 Years
Alger Small Cap Focus Fund Class Z	(5.65)%	(3.50)%	5.28%
Russell 2000 Growth Index	2.42%	7.60%	6.39%
S&P 500 Index	12.10%	15.61%	12.32%

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 857,810,298

Holdings Count | Holding

^[66]

Investment Company Portfolio Turnover

33.24%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$857,810,298
Total number of portfolio holdings¹	51
Portfolio turnover rate	33.24%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Consumer Discretionary	3.7%
Financials	4.1%
Health Care	39.3%
Industrials	24.6%
Information Technology	18.7%
Utilities	3.0%
Short-Term Investments and Other Net Assets	6.6%
	100.0%

^†	Based on net assets.

C000199574 [Member]

Shareholder Report [Line Items]

Fund Name

Alger 35 Fund

Class Name

Class Z

Trading Symbol

ATVPX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger 35 Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger 35 Fund (Class Z / ATVPX)	$28	0.56%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 28

Expense Ratio, Percent

0.56%

^[67]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger 35 Fund generated a 1.66% return for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index and the -1.82% return of the Russell 3000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Communication Services and the largest sector underweight was Financials.

Contributors to Performance

The Communication Services and Health Care sectors were the largest contributors to relative performance. Regarding individual positions, Netflix, Inc., Astera Labs, Inc., Spotify Technology SA, Natera, Inc., and Sea Ltd. were the top five contributors to absolute performance.

Detractors from Performance

The Consumer Discretionary and Information Technology sectors were the largest detractors from relative performance. Regarding individual positions, NVIDIA Corp., Marvell Technology, Inc., Meta Platforms Inc., Enovix Corp., and Cloudflare Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	Since Inception 3/29/18
Alger 35 Fund Class Z	21.21%	13.95%	14.24%
S&P 500 Index	12.10%	15.61%	12.97%
Russell 3000 Growth Index	14.07%	16.71%	15.48%

Performance Inception Date

Mar. 29, 2018

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 31,812,307

Holdings Count | Holding

^[68]

Investment Company Portfolio Turnover

106.52%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$31,812,307
Total number of portfolio holdings¹	34
Portfolio turnover rate	106.52%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	22.3%
Consumer Discretionary	15.7%
Financials	0.5%
Health Care	11.9%
Industrials	8.7%
Information Technology	36.1%
Utilities	4.5%
Short-Term Investments and Other Net Assets	0.3%
	100.0%

^†	Based on net assets.

C000228969 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Focus Fund

Class Name

Class A

Trading Symbol

ALOAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Focus Fund (Class A / ALOAX)	$53	1.09%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 53

Expense Ratio, Percent

1.09%

^[69]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Focus Fund Class A generated a -4.05% return, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Information Technology and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

The Communication Services and Consumer Discretionary sectors were the largest contributors to relative performance. Regarding individual positions, Palantir Technologies Inc., Axon Enterprise Inc., Spotify Technology SA, Natera, Inc., and AppLovin Corp. were the top five contributors to absolute performance.

Detractors from Performance

The Financials and Industrials sectors were the largest detractors from relative performance. Regarding individual positions, FTAI Aviation Ltd., Monolithic Power Systems, Inc., Nebius Group N.V., Clearwater Analytics Holdings, Inc., and Marvell Technology, Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed semi-annual periods for the life of Class A shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 7/29/21
Alger Mid Cap Focus Fund Class A	(1.76)%	(5.83)%
Alger Mid Cap Focus Fund Class A—excluding sales load	3.72%	(4.47)%
Russell Midcap Growth Index	13.65%	2.26%
S&P 500 Index	12.10%	7.98%

Performance Inception Date

Jul. 29, 2021

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 231,760,484

Holdings Count | Holding

^[70]

Investment Company Portfolio Turnover

117.35%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$231,760,484
Total number of portfolio holdings¹	50
Portfolio turnover rate	117.35%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	5.0%
Consumer Discretionary	6.5%
Financials	10.0%
Health Care	14.5%
Industrials	23.7%
Information Technology	28.3%
Materials	2.1%
Real Estate	1.9%
Utilities	3.7%
Short-Term Investments and Other Net Assets	4.3%
	100.0%

^†	Based on net assets.

C000228970 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Focus Fund

Class Name

Class C

Trading Symbol

ALOCX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Focus Fund (Class C / ALOCX)	$92	1.90%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 92

Expense Ratio, Percent

1.90%

^[71]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Focus Fund Class C generated a -4.47% return, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Information Technology and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed semi-annual periods for the life of Class C shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 7/29/21
Alger Mid Cap Focus Fund Class C	1.85%	(5.23)%
Alger Mid Cap Focus Fund Class C—excluding contingent deferred sales charges	2.85%	(5.23)%
Russell Midcap Growth Index	13.65%	2.26%
S&P 500 Index	12.10%	7.98%

Performance Inception Date

Jul. 29, 2021

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 231,760,484

Holdings Count | Holding

^[72]

Investment Company Portfolio Turnover

117.35%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$231,760,484
Total number of portfolio holdings¹	50
Portfolio turnover rate	117.35%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	5.0%
Consumer Discretionary	6.5%
Financials	10.0%
Health Care	14.5%
Industrials	23.7%
Information Technology	28.3%
Materials	2.1%
Real Estate	1.9%
Utilities	3.7%
Short-Term Investments and Other Net Assets	4.3%
	100.0%

^†	Based on net assets.

C000206144 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Focus Fund

Class Name

Class I

Trading Symbol

AFOIX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Focus Fund (Class I / AFOIX)	$55	1.14%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 55

Expense Ratio, Percent

1.14%

^[73]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Focus Fund Class I generated a -4.05% return for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Information Technology and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of each of the most recently completed semi-annual periods for the life of Class I shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	Since Inception 6/14/19
Alger Mid Cap Focus Fund Class I	3.85%	9.74%	10.18%
Russell Midcap Growth Index	13.65%	12.31%	10.60%
S&P 500 Index	12.10%	15.61%	13.62%

Performance Inception Date

Jun. 14, 2019

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 231,760,484

Holdings Count | Holding

^[74]

Investment Company Portfolio Turnover

117.35%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$231,760,484
Total number of portfolio holdings¹	50
Portfolio turnover rate	117.35%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	5.0%
Consumer Discretionary	6.5%
Financials	10.0%
Health Care	14.5%
Industrials	23.7%
Information Technology	28.3%
Materials	2.1%
Real Estate	1.9%
Utilities	3.7%
Short-Term Investments and Other Net Assets	4.3%
	100.0%

^†	Based on net assets.

C000225967 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Focus Fund

Class Name

Class Y

Trading Symbol

ALOYX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Focus Fund (Class Y / ALOYX)	$36	0.74%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 36

Expense Ratio, Percent

0.74%

^[75]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Focus Fund Class Y generated a -3.80% return for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Information Technology and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 2/26/21
Alger Mid Cap Focus Fund Class Y	4.18%	(3.54)%
Russell Midcap Growth Index	13.65%	2.26%
S&P 500 Index	12.10%	7.98%

Performance Inception Date

Feb. 26, 2021

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 231,760,484

Holdings Count | Holding

^[76]

Investment Company Portfolio Turnover

117.35%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$231,760,484
Total number of portfolio holdings¹	50
Portfolio turnover rate	117.35%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	5.0%
Consumer Discretionary	6.5%
Financials	10.0%
Health Care	14.5%
Industrials	23.7%
Information Technology	28.3%
Materials	2.1%
Real Estate	1.9%
Utilities	3.7%
Short-Term Investments and Other Net Assets	4.3%
	100.0%

^†	Based on net assets.

C000206145 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Mid Cap Focus Fund

Class Name

Class Z

Trading Symbol

AFOZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Mid Cap Focus Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Mid Cap Focus Fund (Class Z / AFOZX)	$39	0.80%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 39

Expense Ratio, Percent

0.80%

^[77]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Mid Cap Focus Fund Class Z generated a -3.93% return for the fiscal six-month period ended April 30, 2025, compared to the 2.03% return of the Russell Midcap Growth Index. During the reporting period, the largest sector weightings were Information Technology and Industrials. The largest sector overweight was Information Technology and the largest sector underweight was Consumer Discretionary.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	5 Years	Since Inception 6/14/19
Alger Mid Cap Focus Fund Class Z	3.99%	10.04%	10.47%
Russell Midcap Growth Index	13.65%	12.31%	10.60%
S&P 500 Index	12.10%	15.61%	13.62%

Performance Inception Date

Jun. 14, 2019

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 231,760,484

Holdings Count | Holding

^[78]

Investment Company Portfolio Turnover

117.35%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$231,760,484
Total number of portfolio holdings¹	50
Portfolio turnover rate	117.35%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	5.0%
Consumer Discretionary	6.5%
Financials	10.0%
Health Care	14.5%
Industrials	23.7%
Information Technology	28.3%
Materials	2.1%
Real Estate	1.9%
Utilities	3.7%
Short-Term Investments and Other Net Assets	4.3%
	100.0%

^†	Based on net assets.

C000248571 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Concentrated Equity Fund

Class Name

Class A

Trading Symbol

CNEAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Concentrated Equity Fund (Class A / CNEAX)	$40	0.80%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 40

Expense Ratio, Percent

0.80%

^[79]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Concentrated Equity Fund Class A generated a -0.68% return, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

The Communication Services and Industrials sectors were the largest contributors to relative performance. Regarding individual positions, AppLovin Corp., Netflix, Inc., GFL Environmental Inc., Global-e Online Ltd., and Sea Ltd. were the top five contributors to absolute performance.

Detractors from Performance

The Utilities and Consumer Staples sectors were the largest detractors from relative performance. Regarding individual positions, NVIDIA Corp., Meta Platforms Inc., Taiwan Semiconductor Manufacturing Co., Ltd., Constellation Energy Corp., and Apple Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of the most recently completed semi-annual periods for the life of Class A shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger Concentrated Equity Fund Class A	15.53%	10.58%
Alger Concentrated Equity Fund Class A—excluding sales load	21.89%	16.25%
Russell 1000 Growth Index	14.53%	11.15%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 4,968,463

Holdings Count | Holding

^[80]

Investment Company Portfolio Turnover

35.58%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$4,968,463
Total number of portfolio holdings¹	30
Portfolio turnover rate	35.58%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.1%
Consumer Discretionary	15.6%
Financials	5.1%
Health Care	6.0%
Industrials	9.3%
Information Technology	40.9%
Utilities	4.6%
Short-Term Investments and Other Net Assets	2.4%
	100.0%

^†	Based on net assets.

C000248567 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Concentrated Equity Fund

Class Name

Class C

Trading Symbol

CNECX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Concentrated Equity Fund (Class C / CNECX)	$76	1.55%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 76

Expense Ratio, Percent

1.55%

^[81]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Concentrated Equity Fund Class C generated a -1.02% return, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of the most recently completed semi-annual periods for the life of Class C shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger Concentrated Equity Fund Class C	19.95%	15.41%
Alger Concentrated Equity Fund Class C—excluding contingent deferred sales charges	20.95%	15.41%
Russell 1000 Growth Index	14.53%	11.15%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 4,968,463

Holdings Count | Holding

^[82]

Investment Company Portfolio Turnover

35.58%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$4,968,463
Total number of portfolio holdings¹	30
Portfolio turnover rate	35.58%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.1%
Consumer Discretionary	15.6%
Financials	5.1%
Health Care	6.0%
Industrials	9.3%
Information Technology	40.9%
Utilities	4.6%
Short-Term Investments and Other Net Assets	2.4%
	100.0%

^†	Based on net assets.

C000248568 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Concentrated Equity Fund

Class Name

Class I

Trading Symbol

CNEIX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Concentrated Equity Fund (Class I / CNEIX)	$40	0.80%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 40

Expense Ratio, Percent

0.80%

^[83]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Concentrated Equity Fund Class I generated a -0.68% return for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of the most recently completed semi-annual periods for the life of Class I shares of the Fund. The graph assumes a $10,000 initial investment at the beginning of the first semi-annual period in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger Concentrated Equity Fund Class I	21.89%	16.25%
Russell 1000 Growth Index	14.53%	11.15%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 4,968,463

Holdings Count | Holding

^[84]

Investment Company Portfolio Turnover

35.58%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$4,968,463
Total number of portfolio holdings¹	30
Portfolio turnover rate	35.58%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.1%
Consumer Discretionary	15.6%
Financials	5.1%
Health Care	6.0%
Industrials	9.3%
Information Technology	40.9%
Utilities	4.6%
Short-Term Investments and Other Net Assets	2.4%
	100.0%

^†	Based on net assets.

C000248569 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Concentrated Equity Fund

Class Name

Class Y

Trading Symbol

CNEYX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Concentrated Equity Fund (Class Y / CNEYX)	$27	0.55%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 27

Expense Ratio, Percent

0.55%

^[85]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Concentrated Equity Fund Class Y generated a -0.59% return for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of the most recently completed semi-annual periods for the life of Class Y shares of the Fund. The graph assumes a $500,000 initial investment at net asset value at the inception date of the Fund in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger Concentrated Equity Fund Class Y	22.20%	16.52%
Russell 1000 Growth Index	14.53%	11.15%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 4,968,463

Holdings Count | Holding

^[86]

Investment Company Portfolio Turnover

35.58%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$4,968,463
Total number of portfolio holdings¹	30
Portfolio turnover rate	35.58%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.1%
Consumer Discretionary	15.6%
Financials	5.1%
Health Care	6.0%
Industrials	9.3%
Information Technology	40.9%
Utilities	4.6%
Short-Term Investments and Other Net Assets	2.4%
	100.0%

^†	Based on net assets.

C000248570 [Member]

Shareholder Report [Line Items]

Fund Name

Alger Concentrated Equity Fund

Class Name

Class Z

Trading Symbol

CNEZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger Concentrated Equity Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger Concentrated Equity Fund (Class Z / CNEZX)	$27	0.55%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 27

Expense Ratio, Percent

0.55%

^[87]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger Concentrated Equity Fund Class Z generated a -0.59% return for the fiscal six-month period ended April 30, 2025, compared to the -1.57% return of the Russell 1000 Growth Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Industrials and the largest sector underweight was Consumer Staples.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

The following graph compares the initial and subsequent account values at the end of the most recently completed semi-annual periods for the life of Class Z shares of the Fund. The graph assumes a $500,000 initial investment at net asset value at the inception date of the Fund in an appropriate, broad-based securities market index and a more narrowly based index that reflects the market sector in which the Fund invests for the same period.

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger Concentrated Equity Fund Class Z	22.20%	16.52%
Russell 1000 Growth Index	14.53%	11.15%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 4,968,463

Holdings Count | Holding

^[88]

Investment Company Portfolio Turnover

35.58%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$4,968,463
Total number of portfolio holdings¹	30
Portfolio turnover rate	35.58%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	16.1%
Consumer Discretionary	15.6%
Financials	5.1%
Health Care	6.0%
Industrials	9.3%
Information Technology	40.9%
Utilities	4.6%
Short-Term Investments and Other Net Assets	2.4%
	100.0%

^†	Based on net assets.

C000248576 [Member]

Shareholder Report [Line Items]

Fund Name

Alger AI Enablers & Adopters Fund

Class Name

Class A

Trading Symbol

AIFAX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger AI Enablers & Adopters Fund (Class A / AIFAX)	$43	0.87%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 43

Expense Ratio, Percent

0.87%

^[89]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger AI Enablers & Adopters Fund Class A returned 0.96%, excluding sales load, for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Information Technology and the largest sector underweight was Financials.

Contributors to Performance

The Communication Services and Utilities sectors were the largest contributors to relative performance. Regarding individual positions, Netflix, Inc., Talen Energy Corp., Robinhood Markets, Inc., AppLovin Corp., and Spotify Technology SA were the top five contributors to absolute performance.

Detractors from Performance

The Consumer Staples and Industrials sectors were the largest detractors from relative performance. Regarding individual positions, NVIDIA Corp., Core Scientific Inc., Taiwan Semiconductor Manufacturing Co., Ltd., Meta Platforms Inc., and indie Semiconductor, Inc. were the top five detractors from absolute performance.

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger AI Enablers & Adopters Fund Class A	18.82%	12.99%
Alger AI Enablers & Adopters Fund Class A—excluding sales load	25.39%	18.78%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 5,523,284

Holdings Count | Holding

^[90]

Investment Company Portfolio Turnover

101.71%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$5,523,284
Total number of portfolio holdings¹	53
Portfolio turnover rate	101.71%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	17.3%
Consumer Discretionary	13.4%
Consumer Staples	0.2%
Financials	4.8%
Health Care	3.4%
Industrials	6.9%
Information Technology	47.2%
Real Estate	0.3%
Utilities	7.4%
Short-Term Investments and Other Net Assets	(0.9)%
	100.0%

^†	Based on net assets.

C000248572 [Member]

Shareholder Report [Line Items]

Fund Name

Alger AI Enablers & Adopters Fund

Class Name

Class C

Trading Symbol

AAICX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger AI Enablers & Adopters Fund (Class C / AAICX)	$81	1.63%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 81

Expense Ratio, Percent

1.63%

^[91]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger AI Enablers & Adopters Fund Class C returned 0.54%, excluding contingent deferred sales charge, for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Information Technology and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger AI Enablers & Adopters Fund Class C	23.34%	17.85%
Alger AI Enablers & Adopters Fund Class C—excluding contingent deferred sales charges	24.34%	17.85%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 5,523,284

Holdings Count | Holding

^[92]

Investment Company Portfolio Turnover

101.71%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$5,523,284
Total number of portfolio holdings¹	53
Portfolio turnover rate	101.71%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	17.3%
Consumer Discretionary	13.4%
Consumer Staples	0.2%
Financials	4.8%
Health Care	3.4%
Industrials	6.9%
Information Technology	47.2%
Real Estate	0.3%
Utilities	7.4%
Short-Term Investments and Other Net Assets	(0.9)%
	100.0%

^†	Based on net assets.

C000248573 [Member]

Shareholder Report [Line Items]

Fund Name

Alger AI Enablers & Adopters Fund

Class Name

Class I

Trading Symbol

AIFIX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger AI Enablers & Adopters Fund (Class I / AIFIX)	$43	0.86%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 43

Expense Ratio, Percent

0.86%

^[93]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger AI Enablers & Adopters Fund Class I returned 0.88% for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Information Technology and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $10,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger AI Enablers & Adopters Fund Class I	25.28%	18.69%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 5,523,284

Holdings Count | Holding

^[94]

Investment Company Portfolio Turnover

101.71%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$5,523,284
Total number of portfolio holdings¹	53
Portfolio turnover rate	101.71%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	17.3%
Consumer Discretionary	13.4%
Consumer Staples	0.2%
Financials	4.8%
Health Care	3.4%
Industrials	6.9%
Information Technology	47.2%
Real Estate	0.3%
Utilities	7.4%
Short-Term Investments and Other Net Assets	(0.9)%
	100.0%

^†	Based on net assets.

C000248574 [Member]

Shareholder Report [Line Items]

Fund Name

Alger AI Enablers & Adopters Fund

Class Name

Class Y

Trading Symbol

AAIYX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger AI Enablers & Adopters Fund (Class Y / AAIYX)	$31	0.63%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 31

Expense Ratio, Percent

0.63%

^[95]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger AI Enablers & Adopters Fund Class Y returned 0.96% for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Information Technology and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger AI Enablers & Adopters Fund Class Y	25.47%	18.97%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 5,523,284

Holdings Count | Holding

^[96]

Investment Company Portfolio Turnover

101.71%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$5,523,284
Total number of portfolio holdings¹	53
Portfolio turnover rate	101.71%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	17.3%
Consumer Discretionary	13.4%
Consumer Staples	0.2%
Financials	4.8%
Health Care	3.4%
Industrials	6.9%
Information Technology	47.2%
Real Estate	0.3%
Utilities	7.4%
Short-Term Investments and Other Net Assets	(0.9)%
	100.0%

^†	Based on net assets.

C000248575 [Member]

Shareholder Report [Line Items]

Fund Name

Alger AI Enablers & Adopters Fund

Class Name

Class Z

Trading Symbol

AAIZX

Annual or Semi-Annual Statement [Text Block]

This semi-annual shareholder report contains important information about the Alger AI Enablers & Adopters Fund (“Fund”) for the period of November 1, 2024 to April 30, 2025.

Shareholder Report Annual or Semi-Annual

semi-annual shareholder report

Additional Information [Text Block]

You can find additional information about the Fund at www.alger.com/fundliterature. You can also request this information by contacting us at (800) 992-3863.

Additional Information Phone Number

(800) 992-3863

Additional Information Website

www.alger.com/fundliterature

Expenses [Text Block]

What were the Fund costs for the last six months?

(Based on a hypothetical $10,000 investment)

Fund (Class/Ticker)	Costs of a $10,000 investment	Costs paid as a percentage of a $10,000 investment
Alger AI Enablers & Adopters Fund (Class Z / AAIZX)	$31	0.63%^(a)

^(a)	Annualized.

Expenses Paid, Amount

$ 31

Expense Ratio, Percent

0.63%

^[97]

Factors Affecting Performance [Text Block]

Management's Discussion of Fund Performance

What impacted Fund performance over the reporting period?

Alger AI Enablers & Adopters Fund Class Z returned 1.13% for the fiscal six-month period ended April 30, 2025, compared to the -1.74% return of the S&P 500 Index. During the reporting period, the largest sector weightings were Information Technology and Consumer Discretionary. The largest sector overweight was Information Technology and the largest sector underweight was Financials.

Contributors to Performance

Detractors from Performance

U.S. FACTOR	IMPACT	SUMMARY
Resilient Corporate Earnings	Positive	Strong corporate earnings were driven by profit margin improvement and robust consumer spending. Themes such as cloud-based computing growth and artificial intelligence ("AI") proliferation also supported market sentiment.
AI-Driven Capital Expenditure Wave	Positive	Major U.S. technology firms announced plans exceeding $300 billion in 2025 capital expenditures—primarily targeting AI-related data centers and infrastructure—indicating a durable investment cycle that reinforced growth expectations.
Aggressive Reciprocal Tariffs	Negative	In early April 2025, President Donald Trump announced aggressive “reciprocal” tariffs that were more severe than anticipated, triggering concerns of retaliatory trade actions, supply-chain cost pressure, and weaker global demand for U.S. exports.
Rising Economic Uncertainty	Negative	While U.S. consumer and business spending was strong in the first quarter of 2025, rising economic uncertainty weighed on sentiment. Consumer confidence declined amid elevated inflation expectations, while escalating trade tensions eroded business optimism and reduced international demand for U.S. assets, tempering expectations for future economic growth.

Performance Past Does Not Indicate Future [Text]

Keep in mind that the Fund’s past performance is not a good predictor of how the Fund will perform in the future.

Line Graph [Table Text Block]

Fund Performance

INITIAL INVESTMENT OF $500,000

Average Annual Return [Table Text Block]

Average Annual Total Returns (As of April 30, 2025)	1 Year	Since Inception 4/4/24
Alger AI Enablers & Adopters Fund Class Z	25.68%	19.15%
S&P 500 Index	12.10%	9.06%

Performance Inception Date

Apr. 04, 2024

No Deduction of Taxes [Text Block]

The graph and table do not reflect the deduction of taxes that a shareholder would pay on Fund distributions or redemption of Fund shares.

Updated Performance Information Location [Text Block]

Visit https://www.alger.com/Pages/StrategyFinder.aspx?vehicle=mf for the most recent performance information.

Net Assets

$ 5,523,284

Holdings Count | Holding

^[98]

Investment Company Portfolio Turnover

101.71%

Additional Fund Statistics [Text Block]

Key Fund Statistics

The following table outlines key fund statistics as of the fiscal six-month period ended April 30, 2025.

Fund net assets	$5,523,284
Total number of portfolio holdings¹	53
Portfolio turnover rate	101.71%

¹	Excludes Money Market Funds.

Holdings [Text Block]

^{Sector Allocation} ^†

Communication Services	17.3%
Consumer Discretionary	13.4%
Consumer Staples	0.2%
Financials	4.8%
Health Care	3.4%
Industrials	6.9%
Information Technology	47.2%
Real Estate	0.3%
Utilities	7.4%
Short-Term Investments and Other Net Assets	(0.9)%
	100.0%

^†	Based on net assets.

[1]	Annualized.
[2]	Excludes Money Market Funds.
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[91]	Annualized.
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[93]	Annualized.
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[95]	Annualized.
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[97]	Annualized.
[98]	Excludes Money Market Funds.